Closure arrangement with tear guide for allowing access to zipper flanges in a package

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation-in-part of U.S. patent application Ser. No. 10/131,852, filed on Apr. 25, 2002 now U.S. Pat. No. 6,709,157.

FIELD OF THE INVENTION

The present invention relates generally to opening/closure arrangements for polymeric (plastic) packages and more particularly to a tear guide arrangement for opening a package from a sealed condition.

BACKGROUND OF THE INVENTION

In many consumer packaging applications, it is important to prevent air or water or the like from passing out of or into a package containing certain food products. This is particularly true with respect to cheese packages, meat packages, and the like, for which the contained product must be kept in a constant environment to prevent spoilage. In order to preserve the product contained within such a package, the periphery of the package must be hermetically sealed. Hermetic seals can be provided by both permanent seals and temporary seals known as peelable seals. Peelable seals are capable of providing a hermetic seal and, at the same time, providing a consumer with access to the contents of a package. A consumer breaks a peelable seal of a package by first grabbing onto opposing film faces to which peelable seal materials are adhered and then pulling the film faces apart.

It is also desirable to provide a convenient and effective way to reseal the package after it has been opened. In this respect, reclosable zipper seals are advantageous. On the other hand, reclosable seals alone provide an opportunity for undesired tampering with the contents of a package. To reduce the opportunity for undetected tampering, packages with reclosable zippers can be permanently sealed above or below the reclosable zipper in such in manner that the opening of the package becomes apparent.

However, seals that inhibit tampering may be difficult for the consumer to open. Such seals may require the consumer to break the seals by cutting them with scissors or a knife. To overcome this problem, a perforated tear guide can be combined with a reclosable zipper to provide a package that is easy for the consumer to open and reseal while minimizing the opportunities for undetected pre-sale product tampering.

In many product markets, it is common to use a thermoform packaging machine to package a product. The film for this type of packaging has a tacky sealant layer on its inner side. When two webs of film are brought together, the product and closure arrangement are sealed into the film. The film is also sealed to itself in one or more areas, thereby creating a peelable bond. The outer end of the closure arrangement is then perforated to allow for the end to be removed and to allow access to the zipper or seal. Existing tear guides and closure arrangements are inadequate because the film often gets tucked or sealed into the groove made by the perforation wheel. When this happens, it is difficult to grasp each side of the bag to open the locks of the zipper and ultimately to peel the seal to access the product.

A need therefore exists for a tear guide and closure arrangement for a polymeric package that overcomes the aforementioned shortcomings associated with existing tear guides and closure arrangements.

SUMMARY OF THE INVENTION

Accordingly, the invention described in this application is directed to a reclosable bag comprising convex and concave areas that interact to facilitate opening the bag. To initially open the bag, first and second films are separated from each other by tearing perforations. Next, interlocked closure profiles are detached from each other by grabbing onto gripper ridges and pulling the opening of the bag apart. If the first or second film becomes tucked into the groove left by the perforations such that the gripper ridges are difficult to access even after tearing the perforations, then the end of the opening may be flexed up or down, thereby causing the convex area and concave area to separate and provide access to the gripper ridges.

In an alternate embodiment of the invention, two sets of interlocked closure profiles are initially formed joined to each other and the webs of film attached to each of the pair of interlocked closure profiles. Once the webs of film have been attached to the closure profiles, the pair of interlocked closure profiles are separated along a center slit line such that two packages can be simultaneously formed each utilizing the closure arrangement of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims specifically pointing out and distinctly claiming the subject matter of the invention, it is believed the invention will be better understood from the following description taken in conjunction with the accompanying drawings wherein like reference characters designate the same or similar elements and wherein:

<figref idref="DRAWINGS">FIG. 1</figref> is a sectional view of one embodiment of the present invention, showing an unmated zipper profile and an open concave/convex arrangement;

<figref idref="DRAWINGS">FIG. 2</figref> is a sectional view of the closure arrangement in <figref idref="DRAWINGS">FIG. 1</figref>, wherein the zipper profile is mated and the concave/convex portions are mated;

<figref idref="DRAWINGS">FIG. 3</figref> is a sectional view of the closure arrangement in <figref idref="DRAWINGS">FIG. 1</figref> incorporated into a reclosable bag showing a peel seal located between the bag and the closure arrangement and perforation groove in the holder portion of the closure arrangement;

<figref idref="DRAWINGS">FIG. 4</figref> is a sectional view of the closure arrangement and reclosable bag in <figref idref="DRAWINGS">FIG. 3</figref> wherein the tip of the closure arrangement is removed to provide access to the contents of the reclosable bag;

<figref idref="DRAWINGS">FIG. 5</figref> is a sectional view of the closure arrangement and reclosable bag in <figref idref="DRAWINGS">FIG. 4</figref> after removal of the tip and showing the separation forces generated by flexing the tip in one direction or another;

<figref idref="DRAWINGS">FIG. 5A</figref> is a close-up view of the closure arrangement in <figref idref="DRAWINGS">FIG. 5</figref>;

<figref idref="DRAWINGS">FIG. 6</figref> is a sectional view of the closure arrangement and reclosable bag in <figref idref="DRAWINGS">FIG. 5</figref> showing access to the gripper ridges; and

<figref idref="DRAWINGS">FIG. 7</figref> is a sectional view of a pair of closure arrangements joined to each other wherein the zipper profiles are mated and the concave/convex portions of each closure arrangement are also mated.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to <figref idref="DRAWINGS">FIGS. 1 and 2</figref>, a cross-sectional view of a partial closure arrangement <b>10</b> for a polymeric reclosable bag is shown. The closure arrangement <b>10</b> comprises a first header <b>12</b> having an inner layer <b>16</b>, and a second header <b>14</b> having an inner layer <b>18</b>. Both the first header <b>12</b> and the second header <b>14</b> also include outer sealant layers <b>20</b>, <b>21</b>. The closure arrangement <b>10</b> is preferably disposed at the mouth of a reclosable bag and extends along the length of the bag mouth (not shown).

As shown in <figref idref="DRAWINGS">FIG. 3</figref>, a first film <b>22</b> is preferably attached (e.g heat-fused) to the first header <b>12</b>, and a second film <b>24</b> is attached to the second header <b>14</b>. The films <b>22</b>, <b>24</b> will preferably have a peelable seal <b>26</b> disposed between them as a feature of the overall closure arrangement <b>10</b>. The peel seal is preferably located between the interlocking profiles <b>28</b>, <b>30</b> and the bag <b>25</b> and its contents <b>27</b>. In another embodiment, the peel seal <b>26</b> is located between the interlocking profiles <b>28</b>, <b>30</b> and the top or mouth end <b>29</b> of the bag.

In a preferred embodiment the closure arrangement <b>10</b> includes a reclosable zipper. With reference to <figref idref="DRAWINGS">FIGS. 1 and 2</figref> the inner layers <b>16</b>, <b>18</b> preferably include integrally formed female <b>28</b> and male <b>30</b> closure profiles. For example, the female closure profile <b>28</b> may extend inwardly from the first inner layer <b>16</b> and include a pair of flexible locking members <b>32</b> with hooks at the ends thereof The male closure profile <b>30</b> preferably extends inwardly from the opposite/second inner layer <b>18</b> and includes a single locking member <b>34</b> with an expanded head. The pair of locking members <b>32</b> are disposed opposite the single locking member <b>34</b> and are spaced by a sufficient distance that the expanded head of the single locking member <b>34</b> is releasably engageable between the pair of locking members <b>32</b>. More specifically, the pair of locking members <b>32</b> interlock with the locking member <b>34</b> in a snapping action caused by bringing the hooks of the pair of locking members <b>32</b> past the expanded head of the locking member <b>34</b>.

As shown in <figref idref="DRAWINGS">FIGS. 1 and 2</figref>, the first inner layer <b>16</b> preferably includes a convex area <b>36</b>, and the second inner layer <b>18</b> preferably includes a concave area <b>38</b> at a corresponding location such that the convex area <b>36</b> mates with the concave area <b>38</b> when the first header <b>12</b> and second header <b>14</b> are engaged and the bag is closed. The inner layers <b>16</b>, <b>18</b> each include one or more gripper ridges <b>42</b> to facilitate the gripping and peeling apart of the first header <b>12</b> and second header <b>14</b>.

As shown in <figref idref="DRAWINGS">FIG. 3</figref>, prior to initially opening a bag incorporating the closure arrangement <b>10</b>, the peelable seal <b>26</b> is intact, the closure profiles <b>28</b>, <b>30</b> are interlocked with each other, and the first and second films <b>22</b>, <b>24</b> are preferably connected at the mouth end <b>29</b> of the bag. To facilitate opening, a preferential area of weakness <b>40</b> may be incorporated into the first header <b>12</b> exterior to the convex area <b>36</b>, or into the second header <b>14</b> exterior to the concave area <b>38</b>, or into both (not shown). The preferential area of weakness <b>40</b> may be created with perforations, a knife score, a stress line or a laser score. As shown, the first and second films <b>22</b>, <b>24</b> may be either heat-fused together at the mouth end <b>29</b> of the bag or may be formed from a single piece of film. Since the peelable seal <b>26</b> already provides a hermetic seal for the bag, the first and second films <b>22</b>, <b>24</b> at the mouth end <b>29</b> may alternatively be disconnected from each other.

As shown in <figref idref="DRAWINGS">FIG. 4</figref>, to open the bag, the first and second films <b>22</b>, <b>24</b> are separated from each other by tearing the preferential area of weakness <b>40</b>. However, sometimes the first film <b>22</b> or second film <b>24</b> becomes tucked into the groove left by the preferential area of weakness <b>40</b> such that the gripper ridges <b>42</b> are difficult to access after tearing the preferential area of weakness <b>40</b>. In such cases, the first header <b>12</b> and second header <b>14</b> may be jointly flexed up or down as shown in <figref idref="DRAWINGS">FIGS. 5 and 5A</figref>. This action causes the convex area <b>36</b> and concave area <b>38</b>, by virtue of their corresponding shapes and locations, to separate from each other to create an opening <b>13</b>, thereby providing access to the gripper ridges <b>42</b>. As shown in <figref idref="DRAWINGS">FIG. 6</figref>, the interlocked closure profiles <b>28</b>, <b>30</b> may be detached from each other by grabbing onto the gripper ridges <b>42</b> and pulling the first header <b>12</b> and second header <b>14</b> apart. The interlocked closure profiles <b>28</b>, <b>30</b> and peelable seal <b>26</b> are then separated by continuing to separate the first header <b>12</b> and second header <b>14</b> in opposite directions.

As shown in <figref idref="DRAWINGS">FIG. 7</figref>, in an alternate embodiment of the invention, a first closure arrangement <b>42</b> and a second closure arrangement <b>44</b> can be mated to each other along a center section <b>46</b> such that the two closure arrangements define a dual closure arrangement <b>47</b>. The first closure arrangement <b>42</b> includes a first header <b>50</b> and a second header <b>52</b>, while the second closure arrangement <b>44</b> includes a third header <b>54</b> and a fourth header <b>56</b>. The headers <b>50</b>–<b>56</b> are similar to the headers <b>12</b>, <b>14</b> defined in the previous embodiment of the invention.

As shown in <figref idref="DRAWINGS">FIG. 7</figref>, the first film <b>22</b> is preferably attached (e.g. heat-fused) to the first header <b>50</b> of the first closure arrangement <b>42</b> and the third header <b>54</b> of the second closure arrangement <b>44</b>. Additionally, the first film <b>22</b> is also attached to a connecting portion <b>58</b> joining the pair of headers <b>50</b>, <b>54</b>. The second film <b>24</b> is attached to the second header <b>52</b> of the first closure arrangement <b>42</b> and the fourth header <b>56</b> of the second closure arrangement <b>44</b>. The second film <b>24</b> bridges the opening between the headers <b>52</b>, <b>56</b> as illustrated.

After the first and second films <b>22</b>, <b>24</b> have been attached to the dual profile arrangement shown in <figref idref="DRAWINGS">FIG. 7</figref>, the first closure arrangement <b>42</b> and the second closure arrangement <b>44</b> are separated along a slit line <b>48</b>. Once the closure arrangements <b>42</b>, <b>44</b> have been separated, each of the packages generally takes the form shown in <figref idref="DRAWINGS">FIG. 3</figref>. As previously described with reference to <figref idref="DRAWINGS">FIG. 3</figref>, a peelable seal <b>26</b> provides a hermetic seal for the bag such that the first and second films <b>22</b>, <b>24</b> at the mouth end of the bag can be disconnected from each other.

Once the dual profile arrangement <b>47</b> shown in <figref idref="DRAWINGS">FIG. 7</figref> has been separated, a pair of bags each includes one of the unique closure arrangements of the present invention and can be opened in the manner previously described.

Although the invention has been described in terms of particular embodiments in an application, one of ordinary skill in the art, in light of the teachings herein, can generate additional embodiments and modifications without departing from the spirit of, or exceeding the scope of, the claimed invention. Nothing in the above description is meant to limit the present invention to any specific materials, geometry, or orientation of elements. Many part/orientation substitutions are contemplated within the scope of the present invention and will be apparent to those skilled in the art. Accordingly, it is understood that the drawings, descriptions and examples herein are proffered only to facilitate comprehension of the invention and should not be construed to limit the scope thereof.